Hyperexcitability and Pharmacological Responsiveness of Cortical Neurons Derived from Human iPSCs Carrying Epilepsy-Associated Sodium Channel Nav1.2-L1342P Genetic Variant

• DOI: 10.1523/jneurosci.0564-21.2021
• Publication Date: 2021-10-29T17:50:11Z
• Authors: Zhefu Que; Maria I. Olivero-...; Jingliang Zhang; Muriel Eaton; Anke M. Tukker; Xiaoling Chen; Jiaxiang Wu; Junkai Xie; Tiange Xiao; Kyle Wettschurack; Layan Yunis; J. Marshall Shafer; James A. Schaber; Jean-Christophe R...; Aaron B. Bowman; Chongli Yuan; Zhuo Huang; Chang-Deng Hu; Darci J. Trader; William C. Skarnes; Yang Yang
• Keywords: NAV1; Bursting; Sodium channel blocker

With the wide adoption of genomic sequencing in children having seizures, an increasing number SCN2A genetic variants have been revealed as causes epilepsy. Voltage-gated sodium channel Nav1.2, encoded by gene , is predominantly expressed pyramidal excitatory neurons and supports action potential (AP) firing. One recurrent variant L1342P, which was identified multiple patients with epileptic encephalopathy intractable seizures. However, mechanism underlying L1342P-mediated seizures pharmacogenetics this human remain unknown. To understand core phenotypes L1342P neurons, we took advantage a reference human-induced pluripotent stem cell (hiPSC) line from male donor, introduced CRISPR/Cas9-mediated genome editing. Using patch-clamping microelectrode array (MEA) recordings, that cortical derived hiPSCs carrying heterozygous significantly increased intrinsic excitability, higher current density, enhanced bursting synchronous network firing, suggesting hyperexcitability phenotypes. Interestingly, neuronal culture displayed degree resistance to anticonvulsant medication phenytoin, recapitulated aspects clinical observation variant. In contrast, phrixotoxin-3 (PTx3), Nav1.2 isoform-specific blocker, can potently alleviate spontaneous chemically-induced Our results reveal possible pathogenic underpinning Nav1.2-L1342P mediated demonstrate utility genome-edited vitro platform advance personalized phenotyping drug discovery. SIGNIFICANCE STATEMENT A mounting epilepsy, but how affect function contributing still elusive. This study investigated functional consequences recurring (L1342P) using iPSC-derived both mutant channel. Importantly, elements observations drug-resistant features variant, provided for testing. sheds light on cellular resulting helps discovery treat